Power saving mechanism for MU-MIMO transmissions

ABSTRACT

Techniques for power saving by remote wireless mobile devices are provided, in particular by stations (STAs) during downlink (DL) multiple-user multiple-input and multiple-output (MU-MIMO) transmissions in an Institute of Electrical and Electronics Engineers (IEEE) 802.11ay network when reverse direction (RD) transmissions are either enabled and not enabled. Various embodiments enable each STA in a group of STAs to determine an order in which the STAs are requested to send a block acknowledgement (BACK) and which STAs will be granted an RD transmission. Further, a duration of each RD transmission is provided to each STA. Based on the provided information, each STA can determine times to enter a power saving mode. Other embodiments are described and claimed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, claims the benefit of andpriority to previously filed U.S. patent application Ser. No. 16/786,638filed Feb. 10, 2020, entitled “POWER SAVING MECHANISM FOR MU-MIMOTRANSMISSIONS”, which is a continuation of, claims the benefit of andpriority to previously filed U.S. patent application Ser. No. 15/712,101filed Sep. 21, 2017, entitled “POWER SAVING MECHANISM FOR MU-MIMOTRANSMISSIONS”, which is a continuation of, claims the benefit of andpriority to previously filed U.S. patent application Ser. No. 15/390,376filed Dec. 23, 2016, entitled “POWER SAVING MECHANISM FOR MU-MIMOTRANSMISSIONS”, which are hereby incorporated by reference in theirentireties.

TECHNICAL FIELD

Embodiments described herein generally relate to wireless communicationsbetween devices in wireless networks.

BACKGROUND

Many conventional wireless systems do not provide opportunities forremote mobile devices to enter power saving modes. For example,currently, the Institute of Electrical and Electronics Engineers (IEEE)802.11ay standard does not provide for power saving during downlink (DL)multiple-user multiple-input and multiple-output (MU-MIMO)transmissions. Accordingly, new techniques for proving power savingduring DL MU-MIMO transmissions, with and without reverse direction (RD)transmission allowed, may be needed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of a first operating environment.

FIG. 2 illustrates an exemplary communication flow between elementsdepicted in FIG. 1 .

FIG. 3 illustrates an exemplary data frame.

FIG. 4 illustrates an embodiment of a first logic flow.

FIG. 5 illustrates an embodiment of a second logic flow.

FIG. 6 illustrates an embodiment of a storage medium.

FIG. 7 illustrates an embodiment of a device.

FIG. 8 illustrates an embodiment of a wireless network.

DETAILED DESCRIPTION

Various embodiments may be generally directed to power saving by remotewireless mobile devices, in particular by stations (STAs) duringdownlink (DL) multiple-user multiple-input and multiple-output (MU-MIMO)transmissions in an Institute of Electrical and Electronics Engineers(IEEE) 802.11ay network when reverse direction (RD) transmissions areeither enabled and not enabled. Various embodiments enable each STA in agroup of STAs to determine an order in which the STAs are requested tosend a block acknowledgement (BACK) and which STAs will be granted an RDtransmission. Further, a duration of each RD transmission is provided toeach STA. Based on the provided information, each STA can determinetimes to enter a power saving mode. Other embodiments are described andclaimed.

Various embodiments may comprise one or more elements. An element maycomprise any structure arranged to perform certain operations. Eachelement may be implemented as hardware, software, or any combinationthereof, as desired for a given set of design parameters or performanceconstraints. Although an embodiment may be described with a limitednumber of elements in a certain topology by way of example, theembodiment may include more or less elements in alternate topologies asdesired for a given implementation. It is worthy to note that anyreference to “one embodiment” or “an embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment. The appearances ofthe phrases “in one embodiment,” “in some embodiments,” and “in variousembodiments” in various places in the specification are not necessarilyall referring to the same embodiment.

Various embodiments herein are generally directed to wirelesscommunications systems. Some embodiments are particularly directed towireless communications over 31.8 GHz and/or 60 GHz frequencies. Varioussuch embodiments may involve wireless communications performed accordingto one or more standards for 60 GHz wireless communications and/orwireless communications over 31.8 GHz. For example, some embodiments mayinvolve wireless communications performed according to one or moreWireless Gigabit Alliance (“WiGig”)/Institute of Electrical andElectronics Engineers (IEEE) 802.11ad standards, such as IEEE802.11ad-2012, including their predecessors, revisions, progeny, and/orvariants. Various embodiments may involve wireless communicationsperformed according to one or more “next-generation” 60 GHz (“NG60”)wireless local area network (WLAN) communications standards, such as theIEEE 802.11ay standard that is currently under development. Someembodiments may involve wireless communications performed according toone or more millimeter-wave (mmWave) wireless communication standards.It is worthy of note that the term “60 GHz” (or any specific frequency),as it is employed in reference to various wireless communicationsdevices, wireless communications frequencies, and wirelesscommunications standards herein, is not intended to specifically denotea frequency of exactly 60 GHz (or any other specific frequency), butrather is intended to generally refer to frequencies in, or near, the 57GHz to 64 GHz frequency band or any nearby unlicensed band. Theembodiments are not limited in this context.

In general, various embodiments herein may involve millimeter-wavecommunications systems. Various embodiments herein may involve systemsoperating according to any known wireless standard or protocol or anywireless standard or protocol under development including, but notlimited to, IEEE 802.11ad, IEEE 802.11ay, and any 5G system.

Various embodiments may additionally or alternatively involve wirelesscommunications according to one or more other wireless communicationstandards. Some embodiments may involve wireless communicationsperformed according to one or more broadband wireless communicationstandards. For example, various embodiments may involve wirelesscommunications performed according to one or more 3rd GenerationPartnership Project (3GPP), 3GPP Long Term Evolution (LTE), and/or 3GPPLTE-Advanced (LTE-A) technologies and/or standards, including theirpredecessors, revisions, progeny, and/or variants. Additional examplesof broadband wireless communication technologies/standards that may beutilized in some embodiments may include—without limitation—GlobalSystem for Mobile Communications (GSM)/Enhanced Data Rates for GSMEvolution (EDGE), Universal Mobile Telecommunications System (UMTS)/HighSpeed Packet Access (HSPA), and/or GSM with General Packet Radio Service(GPRS) system (GSM/GPRS), IEEE 802.16 wireless broadband standards suchas IEEE 802.16m and/or IEEE 802.16p, International MobileTelecommunications Advanced (IMT-ADV), Worldwide Interoperability forMicrowave Access (WiMAX) and/or WiMAX II, Code Division Multiple Access(CDMA) 2000 (e.g., CDMA2000 1×RTT, CDMA2000 EV-DO, CDMA EV-DV, and soforth), High Performance Radio Metropolitan Area Network (HIPERMAN),Wireless Broadband (WiBro), High Speed Downlink Packet Access (HSDPA),High Speed Orthogonal Frequency-Division Multiplexing (OFDM) PacketAccess (HSOPA), High-Speed Uplink Packet Access (HSUPA) technologiesand/or standards, including their predecessors, revisions, progeny,and/or variants.

Further examples of wireless communications technologies and/orstandards that may be used in various embodiments may include—withoutlimitation—other IEEE wireless communication standards such as the IEEE802.11, IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE802.11u, IEEE 802.11ac, IEEE 802.11af, and/or IEEE 802.11ah standards,High-Efficiency Wi-Fi standards developed by the IEEE 802.11 HighEfficiency WLAN (HEW) Study Group and/or IEEE 802.11 Task Group (TG) ax,Wi-Fi Alliance (WFA) wireless communication standards such as Wi-Fi,Wi-Fi Direct, Wi-Fi Direct Services, WiGig Display Extension (WDE),WiGig Bus Extension (WBE), WiGig Serial Extension (WSE) standards and/orstandards developed by the WFA Neighbor Awareness Networking (NAN) TaskGroup, machine-type communications (MTC) standards such as thoseembodied in 3GPP Technical Report (TR) 23.887, 3GPP TechnicalSpecification (TS) 22.368, and/or 3GPP TS 23.682, and/or near-fieldcommunication (NFC) standards such as standards developed by the NFCForum, including any predecessors, revisions, progeny, and/or variantsof any of the above. The embodiments are not limited to these examples.

FIG. 1 illustrates an exemplary operating environment 100 such as may berepresentative of various embodiments in which techniques for powersaving are implemented. The operating environment 100 can include awireless communication device (WCD) 102, a WCD 104, a WCD 106, and a WCD108. The WCDs 102-108 can communicate with one another wirelessly. As anexample, the WCD 102 and the WCD 104 can communicate over a wirelesscommunications interface 110. The wireless communications interface 110can be, for example, a wireless interface for any of the wirelessnetworks or standards described herein including, for example, acommunication standard including an IEEE 802.11 standard such as, forexample, 802.11ad or 802.11ay, or a 5G communication standard. Invarious embodiments, the wireless interface 110 may operate within a 60GHz frequency band and/or any band over 31.8 GHz. In variousembodiments, the wireless interface 110 can be a millimeter-wavecommunication interface. The same wireless interface 110 can be used forcommunications between any of the WCDs 102-108.

In various embodiments, at least one of the WCDs 102-108 may operate asa station (STA) and at least one of the WCDs 102-108 may operate as apersonal basic service set (PBSS) control point (PCP) or infrastructurebasic service set (BSS) access point (AP). One or more of the WCDs102-108 can be, for example, a mobile computing device. As an example,the WCDs 102-108 can be any mobile computing device capable ofcommunicating wirelessly over one or more wireless communicationnetworks. In various embodiments, at least one of the WCDs 102-104 canbe a user equipment (UE) and at least one of the WCDs 102-104 can be acellular base station such as, for example, an evolved node B (eNB).

In various embodiments described herein, the WCD 102 can be consideredto be an AP/PCP (e.g., AP/PCP 102) and the other WCDs 104-108 can beconsidered to be STAs (e.g., STAs 104-108). Further, the AP/PCP 102 andthe STAs 104-108 can operate as part of an IEEE 802.11ay communicationsystem of which the operating environment 100 is a part such that thecommunications interface 106 operates according to IEEE 802.11ay.Additionally, the STAs 104-108 can be multiple-user multiple-input andmultiple-output (MU-MIMO) STAs and can operate within an 802.11aynetwork that supports reverse direction (RD) for downlink (DL) MU-MIMOas described in U.S. Appl. No. 62/380,672, filed on Aug. 29, 2016 andU.S. Appl. No. 62/363,596, filed on Jul. 18, 2016, both of which arehereby incorporated by reference in their entirety. The STAs 104-108 canrepresent an MU-MIMO group of STAs. For simplicity, three STAs 104-108are shown in FIG. 1 for simplicity but the operating environment 100 isnot so limited as any number of STAs can operate as part of a MU-MIMOgroup in relation to the AP/PCP 102. The AP/PCP 102 and the STAs 104-108can implement the power saving mode techniques described herein. Theembodiments are not limited in this context.

FIG. 2 illustrates opportunities for entering a power saving mode duringan RD communication flow between the AP/PCP 102 and the STAs 104-108. Asshown in FIG. 2 , STA “1” can be considered to be STA 104, STA “2” canbe considered to be STA 106, and STA “3” can be considered to be STA108. STA 1 can represent the first STA to send a Block Acknowledgement(BlockACK) to the AP 102 after receiving a first MU PHY layerconvergence procedure (PLCP) protocol data unit (PPDU), STA 3 canrepresent the last STA to send a BlockACK in response to the first MUPPDU, and STA2 can represent any STA between the first and last STA tosend a BlockAck in response to the MU PPDU.

FIG. 2 illustrates the communications and/or information transmitted andreceived by the AP 102 and the STAs 104-108 over time. For example, foreach timeline shown, transmitted information is represented by blockspositioned above the timelines and received information is representedby blocks positioned beneath the timelines. For simplicity, informationtransmitted by the STAs 104-108 and received by the AP 102 is not shownfor simplicity. FIG. 2 shows situations in which the STAs 104-108 withinan MU-MIMO group may enter power saving mode during the DL MU-MIMOtransmissions.

As shown in FIG. 2 , the AP 102 transmits an aggregated medium accesscontrol (MAC) protocol data unit (AMPDU) 202 to STA 104, an AMPDU 204 toSTA 106, and an AMPDU 206 to STA 108. The AMPDUs 202-206 are received bythe STAs 104-106, respectively. In response to receiving the AMPDU 202,the STA 104 can be requested to approximately immediately send aBlockACK 208 in response. In combination with the BlockACK 208, the STA104 can send any RD data if granted RD data from the AP 102 (BlockACKand RD data shown together as “BACK 1+RD DATA” element 208). The STA 104can then receive a BlockACK 210 from the AP 102. As shown by thetimeline for STA 104, STA 104 can be active for (1) receiving the AMPDU202 (e.g., an MU PPDU), (2) sending its BlockACK and RD data 208 ifgranted RD, and (3) receiving the following BlockACK 210 from the AP 102if its RD data requires an acknowledgement. Subsequent to theseoperations, the STA 104 may enter a power saving mode indicated as sleep212. The STA 104 may remain in the power saving mode/sleep 212 until theAP 102 transmits the AMPDU 214 (e.g., the next MU PPDU). FIG. 2therefore shows the opportunity for STA 104 to enter a power saving modegiven that it is the first STA in the MU-MIMO STA group to send aBlockACK (and possibly RD data) for a current MU PPDU.

The operation of STA 106 is described next. The STA 106 can representany STA within a network that is neither the first STA nor the last STAin the MU-MIMO group to be requested to send a BlockACK. Under such ascenario, the STA 106 can enter a power saving mode indicated as sleep216 after receiving the AMPDU 204. The STA 106 can remain in the powersaving mode/sleep 216 until the AP 102 sends a Block AcknowledgementRequest (BlockACKReq; represented as “BAR”) 212 with or without an RDgrant to the STA 106. The BAR 212 can also include quality of service(QoS) null data. In response to the BAR+QoS null data 212, the STA 106can transmit a BlockACK with any RD data if granted RD data from the AP102 (BlockACK and RD data shown together as “BACK 1+RD DATA” element214). The STA 106 can then receive a BlockACK 216 from the AP 102. TheSTA 106 may then enter another power saving mode indicated as sleep 218until the AP 102 transmits the AMPDU 220 (e.g., the next MU PPDU). FIG.2 therefore shows the opportunity for STA 106 to enter a power savingmode given that it is neither the first nor the last STA in the MU-MIMOSTA group to send a BlockACK (and possibly RD data) for a current MUPPDU.

The operation of STA 108 is described next. The STA 108 can representthe last STA in the MU-MIMO group to be requested to send a BlockACK.Under such a scenario, the STA 108 can enter a power saving modeindicated as sleep 222 after receiving the AMPDU 206. The STA 108 canremain in the power saving mode/sleep 222 until the AP 102 sends aBlockACKReq 224 with or without an RD grant to the STA 108. The BAR 224can also include quality of service (QoS) null data. In response to theBAR+QoS null data 224, the STA 108 can transmit a BlockACK with any RDdata if granted RD data from the AP 102 (BlockACK and RD data showntogether as “BACK 1+RD DATA” element 226). The STA 108 can remain activeto receive an acknowledgement from the AP 102 if necessary (not shown inFIG. 2 for simplicity) and can also remain active to receive AMPDU 228(e.g., the next MU PPDU). FIG. 2 therefore shows the opportunity for STA108 to enter a power saving mode given that it is the last STA in theMU-MIMO STA group to send a BlockACK (and possibly RD data) for acurrent MU PPDU.

Techniques provided herein enable the MU-MIMO destination STAs 104-108to enter a power saving mode according to any of the three scenariosdescribed above in relation to FIG. 2 —for STAs that are the first totransmit a BlockACK, for STAs that are the last to transmit a BlockACK,or for STAs that are neither the first nor the last to transmit aBlockACK for a current MU PPDU. The techniques provided herein ensurethat each STA 104-108 is provided with the following information: (1)the order in which the STAs 104-108 will be requested for BlockACK fromthe AP 102; (2) for each of the STAs 104-108 that will be requested forBlockACK from the AP 102, whether RD will be granted; and (3) for eachof the STAs 104-108 that will be granted RD, the duration or amount oftime that will be given for providing the RD response burst.

In various embodiments, the order in which the STAs 104-108 will berequested for BlockACK from the AP 102 can be indicated using anenhanced directional multi-gigabit (EDMG) Header A (and/or EDMG HeaderB) of an MU PPDU. In the EDMG Header A, the association identifiers(AIDs) of all the addressed STAs in the MU-MIMO group can be listed(e.g., the AIDs corresponding to the STA 104-108). In variousembodiments, eight AIDs can be included in the EDMG Header A,corresponding to a maximum MU-MIMO group size. In various embodiments,the AP 102 may not request BlockACKs from all the addressed STAs.Accordingly, eight bits (e.g., one byte) of BACK indication in EDMGHeader A and/or EDMG Header B, with each bit corresponding to an AID,can be used to indicate whether the STA will be requested BlockACK for acurrent MU PPDU.

FIG. 3 illustrates an exemplary data frame 300 according to variousembodiments. The data frame can be an EDMG Header A. The EDMG Header A300 can be prepared or generated by the STA 102. As shown in FIG. 3 ,the EDMG Header A 300 includes the AIDs 302 for the maximum number ofSTAs that can be in a MU-MIMO group. The AIDs 302 for the STAs arelisted sequentially. The EDMG Header A 300 further includes a BACKindication 304. The bit-by-bit breakdown of the BACK indication 304 isshown by the sequential bit listing 304-A (e.g., comprising 1 byte or 8bits). The bit-by-bit breakdown 304-A of the BACK indication 304corresponds to the sequential listing of AIDs—for example, such that AID1 corresponds to the first bit position in bit listing 304-A, AID 2corresponds to the second bit position in bit listing 304-A, etc.

A “1” in the BACK indication 304 indicates that a corresponding STA(linked by the AID 302) will be requested for a BlockACK from the AP 102with the sequential listing of the AIDs 302 indicating the order inwhich they will be requested. For the exemplary EDMG Header A 300 ofFIG. 3 , AIDs 1-6 will be requested for BlockACK with respect to acurrent MU PPDU, while AIDs 7-8 will not be requested for BlockACK.Further, the AIDs 1-6 will be requested in the order listed in thebreakdown 304-A (i.e., sequentially).

In various embodiments, the AP 102 may not grant RD to each of the STAsin the MU-MIMO group. Accordingly, in various embodiments, a secondportion of the EDMG Header A can be used to indicate whether aparticular STA will be granted RD. The second portion can also be a byte(e.g., 8 bits) with each bit corresponding to a particular AID. A “1”can indicate that RD is granted for a particular AID and a “0” canindicate that RD is not granted. Overall, each bit in the additionalbyte corresponding to an AID will indicate whether the STA will begranted RD for a current MU PPDU. Note that an MU-MIMO destination STAshall not be granted RD when it is not requested by the AP 102 forBlockACK.

FIG. 3 illustrates the EDMG Header A 300 that includes an RD indication306. The RD indication 306 can be a field that is part of the EDMGHeader A 300. The RD indication 306 can be a byte positioned after theBACK indication byte 304. A bit-by-bit breakdown 306-A of the RDindication is also shown in FIG. 3 . For the RD indication 306, asdiscussed above, each bit field corresponds to a particular STA AID 302.Further, a “1” positioned in the bit field of 306-A can indicate RD willbe granted to the STA having the corresponding AID 302. A “0” positionedin the bit field of 306-A can indicate RD will not be granted to the STAhaving the corresponding AID 302. Note in the exemplary EDMG Header A300, AID 1, AID 4, and AID 6 will be granted RD. Further, note that AIDs7-8 are not granted RD since these AIDs are not requested for BlockACK.In various embodiments, if the EDMG Header A 300 does not have enoughbits left for the BACK indication byte 304 and RD indication byte 306,then an EDMG Header B can be used to provide one or both of theseindicators.

In various embodiments, the BACK indication and the RD indication can beprovided by a management frame that can include the BACK indication andRD indication bytes illustrated above (e.g., the BACK indication304/304-A and the RD indication 306/306-A). For each MU PPDU, the AP 102can aggregate this management frame to the AMPDUs that are addressed tothe MU-MIMO destination STAs (e.g., AMPDUs 202-206). Once an MU-MIMOdestination STA receives the MU PPDU, the STA can determine which AIDsare going to be requested for BlockACK and which AIDs are going to begranted RD by referring to the AID order indicated in the EDMG Header A.

In various embodiments, the AP 102 can announce the duration of the RDresponse burst for each MU-MIMO destination STA to all MU-MIMO groupmembers before the AP 102 collects BlockACK and RD data for an MU PPDU.The duration of the RD responder burst for each MU-MIMO destination STAcan be included, for example, in the EDMG Header A 300 or an EDMG HeaderB. Alternatively, the duration of the RD responder burst can be providedby any other technique that distributes the RD duration information toall members of the MU-MIMO group. As an example, the RD durationinformation can be included in one or more MU-MIMO setup frames providedahead of, or at the beginning of, an MU-MIMO transmission opportunity(TXOP).

An MU-MIMO destination STA that is provided with the informationdescribed above—that is, (1) the order of STAs that the AP 102 willrequest for BlockACK; (2) whether RD will be granted to a particularSTA; and (3) the duration for transmitting any RD responder burst—cansubsequently determine when it should be active and when it can enter apower saving mode. To facilitate a determination of how long to enter apower save mode and when to enter and exit a power saving mode, invarious embodiments, an STA can assume BlockACK and BlockACKReq+QoS Nulltransmissions will be sent using modulation coding scheme (MCS) 4 asspecified in 802.11ay. Further, an STA can assume use of the shortestbitmap length of BlockACK when calculating the duration of a BlockACKtransmission.

In various embodiments, three different options can be provided to anSTA in determining whether to enter a power saving mode during the RDtransmissions of other STAs. As a first exemplary option, an STA mayenter power saving mode during the RD transmissions of other STAs. Thisoption can ensure the longest power saving time for an STA but may relyon (1) that the AP 102 has an accurate estimation so that each RDresponder has enough RD data to transmit during its assigned duration ofRD responder burst; and (2) that an MU-MIMO destination STA will occupythe channel until the end of the RD responder burst duration that it wasassigned by the AP 102.

As a second exemplary option, an STA does not enter power saving modeduring the RD transmissions of other STAs. This option does not rely onan accurate estimation on RD duration from the AP 102 and allows the AP102 to take over the channel once the RD responder finishes its RDresponse burst. This option provides the shortest power saving time, butmay be less complicated than the first option. Further, when an STAoperates under option 2, it can be assured that the STA will alwayswakeup in time and will not miss any information transmitted to it bythe AP 102.

As a third exemplary option, an STA may enter power saving mode for aportion of the RD transmissions of the other STAs. The portion can be apercentage (e.g., X % of the duration). The determined percentage canimplementation specific, can vary across each STA, and can vary overtime for any particular STA. This option can provide for more powersaving opportunities compared to option 2 while relying on less accuracyon RD duration estimation when compared to option 1. Further, thisoption also allows for the AP 102 to take over the channel once an RDresponder has completed its RD data transmission.

Based on the techniques described herein, an STA (e.g., one of the STAs104-108) can determine whether it will be the first, last, or neitherthe first or last STA to be requested to transmit a BlockACK for acurrent MU PPDU—for example, based on information provided in an EDMGHeader (e.g., EDMG Header A 300). Further, an STA can determine if it isgranted an opportunity to transmit RD data (e.g., based on informationprovided in the EDMG Header A 300) as well as a duration of a RD burst.Once provided with this information, an STA can subsequently determinewhen to enter a power saving mode based on one of the three optionsdiscussed above such that the STA can exit the power saving mode/wake-upto receive a BlockACKReq, a BlockACKReq+QoS-Null transmission, or a nextMU-PPDU.

In various embodiments, the techniques described herein for an MU-MIMOgroup STA to determine when to enter a power saving mode can be used inthe case of MU-MIMO transmission without RD. When RD is not provided,the AP 102 may not estimate a RD response burst duration for eachdestination STA. Further, the RD indication 306 may be set to all “0”sor may be excluded in the EDMG Header A or EDMG Header B. Additionally,an STA can use option 2 described above to calculate its sleepingtime(s) and wakeup time(s).

In various embodiments, the WCDs 102-108 can transmit data orinformation as part of a data message, frame, or signal over a wirelesscarrier. In various embodiments, any data message, frame, or signal canbe transmitted and received wirelessly according to 802.11ay. The EDMGHeader A depicted in FIG. 3 (as well as an EDMG Header B or any othermanagement or data frame described herein) can be a portion or datamessage, a signal, or frame. As an example, the listing of AIDs 102, theBACK indication field 304, and the RD indication field 306 (and theduration information regarding each RD burst) can be part of a message,signal, or frame that forms part of the EDMG Header A and/or part of theEDMG Header B or any other management or setup frame.

FIG. 4 illustrates an example of a logic flow 400 that may berepresentative of the operation of an AP/PCP according to variousembodiments. For example, logic flow 400 may be representative ofoperations that may be performed in various embodiments by wirelesscommunication device 102 in operating environment 100 of FIG. 1 whenoperating as an AP/PCP in an 802.11ay network. Logic flow 400 may berepresentative of an AP/PCP 802.11ay device that generates and transmitsthe exemplary data frame 300 of FIG. 3 to a group of MU-MIMO STAs (e.g.,the STAs 104-108 of FIG. 1 ).

As shown in FIG. 4 , at 402, the AP/PCP can indicate the order that theSTAs in the group will be requested to transmit a BlockACK. The BlockACKcan be requested to be sent in response to an MU PPDU. The order can beindicated based on the data frame 300. In particular, the AP/PCP cangenerate the data frame 300 (e.g., an EDMG Header A 300) to indicate theorder based on the listing of AIDs 302 and the BACK indication 304. Thelisting of AIDs can be a sequential listing of the AIDs for each of theSTAs in the group. The BACK indication can include a bit sequence witheach bit position corresponding to one of the AIDs in the listing of theAIDs. In the BACK indication, a “1” value in a bit position can indicatethat a BlockACK will be requested from the STA associated with the AIDcorresponding to the bit position. A “0” value in a bit position canindicate that a BlockACK will not be requested from the STA associatedwith AID corresponding to the bit position. Based on the listing of AIDsand the corresponding BACK indication bits, the STAs that will berequested to send a BlockACK and the order in which the STAs will berequested to send the BlockACK can be provided. Overall, the bitposition of each bit in the BACK indication can corresponding to aparticular AID of a STA while the bit value can indicate whether aBlockACK will be requested for that particular STA corresponding to theAID.

At 404, for each STA that will be requested to send a BlockACK, theAP/PCP can indicate which of these STAs will be granted an RDtransmission. The RD grants can be indicated using the data frame 300.In particular, the grant can be indicated using an RD indication fieldin the EDMG Header A 300. The RD indication can include a bit sequencewith each bit position corresponding to one of the AIDs in the listingof the AIDs. In the RD indication, a “1” value in a bit position canindicate that RD transmission will be granted to the STA thatcorresponds the AID associated with that bit position. A “0” value inthe bit position can indicate that an RD transmission will not begranted to the STA that corresponds to the AID associated with that bitposition.

For 402 and 404, the listing of AIDs for the STAs in the group can besequential (i.e., in order from AID 1, AID 2, . . . AID 8). The listingof AIDs can have a maximum number of included AID fields (e.g., amaximum of eight). Further, the BACK indication and RD indication fieldscan include a number of bit fields that match the maximum number ofpossible AIDs (e.g., eight bits or 1 byte). The sequential listing ofthe bits in the BACK indication filed and the RD indication filed cancorrespond to the sequential listing of the AIDs. In this way, each STAcan determine an order of the STAs, what STAs are to be expected to senda BlockACK, and what STAs are to be granted an RD transmissionopportunity.

At 406, for each STA that will be granted an RD transmissionopportunity, the AP/PCP can indicate the duration of the RD burst foreach STA. The duration of an RD burst or transmission by a particularSTA can be indicated in the data frame 300 (e.g., the EDMG Header A 300or in an EDMG Header B). The duration of an RD burst or transmission bya particular STA can alternatively be indicted using one or more setupframes transmitted by the AP/PCP prior to transmission of an MU PPDU forwhich the indications are provided. The embodiments are not limited tothese examples.

FIG. 5 illustrates an example of a logic flow 500 that may berepresentative of the operation of an STA according to variousembodiments. For example, logic flow 500 may be representative ofoperations that may be performed in various embodiments by one of thewireless communication devices 104-108 in operating environment 100 ofFIG. 1 when operating as an STA in an 802.11ay network. Logic flow 500may be representative of an STA 802.11ay device that receives andprocesses the exemplary data frame 300 of FIG. 3 from an AP/PCP (e.g.,the AP/PCP 102 of FIG. 1 ).

As shown in FIG. 5 , at 502 an order in which the STAs in an MU-MIMOgroup will be requested for BlockACK can be determined. As discussedabove in relation to FIGS. 3 and 4 , the order can be indicated using alisting of the AIDs of the STAs in conjunction with a BACK indicationfield. The listing of the AIDs and the BACK indication field can beprovided in a data from provided to each STA—that is, transmitted by theAP/PCP and received and processed by each STA. Each STA can use thelisting of AIDs and the BACK indication field to determine its orderamong the group of STAs as well as determine if the AP/PCP expects it tosend a BlockACK in response to a current MU PPDU. The listing of theAIDs and the BACK indication can be provided in the EDMG Header A 300 orin an EDMG Header B as discussed above.

At 504, a determination can be made by each STA that is expected to senda BlockACK whether the STA will be granted an RD transmission. Asdiscussed above in relation to FIGS. 3 and 4 , the indication can beprovided by an RD indication field. The RD indication field can specifywhether a particular STA will be granted RD or not. The RD indicationcan be provided in the EDMG Header A 300 or in an EDMG Header B asdiscussed above.

At 506, a determination can be made by each STA that has been granted anRD transmission of the duration of the granted RD burst. The duration ofeach RD burst provided to the STAs granted an RD can be provided to allSTAs. The duration information can be provided in in the EDMG Header A300 or in an EDMG Header B as discussed above or can be provided in oneor more setup frames transmitted by the AP/PCP prior to transmitting anMU PPDU.

At 508, each STA in the group of MU-MIMO STAs can have knowledge of (1)the order in which the STAs will be expected to provide a BlockACK, (2)which STAs will be granted RD, and (3) the duration of the RD burst foreach STA granted RD. This knowledge can be provided based on theindications provided in 502-506. Based on this information, at 508, eachSTA can determine when to enter a power saving mode (e.g., when to entera power saving mode and when to exit a power saving mode). As discussedabove, each STA can determine when it should be active and when it canbe in a sleep or low power mode based on entering a power saving modeduring the RD transmissions of the other STAs (e.g., option 1 asdescribed above), not entering a power saving mode during the RDtransmissions of the other STAs (e.g., option 2 as described above), orentering a power saving mode for a portion of the RD transmissions ofthe other STAs (e.g., option 3 as described above).

Logic flow 500 enables a STA to determine whether it will be the firstSTA to be expected to send a BlockACK, the last STA to be expected tosend a BlockACK, or some other order of STA other than the first or lastSTA to be expected to send a BlockACK for a current MU PPDU as describedabove in relation to FIG. 2 . An STA can then determine when to enter apower saving mode (e.g., a sleep mode or a low power mode) and when toexit a power saving mode (e.g., when to wake up or become active) toensure reception of a BlockACKReq transmission, a BlockACKReq+QoS-Nulltransmission, or a next MU PPDU. The embodiments are not limited tothese examples.

Techniques described herein enable power saving during DL MU-MIMOtransmissions with and without RD. Overall, the techniques enable anAP/PCP (e.g., the AP 102) to announce the RD duration of each MU-MIMOdestination STA ahead of the AP/PCP collecting BlockACK and RD data fromthe STAs. By announcing the RD duration of each ATA, every MU-MIMOdestination STA has the knowledge of RD duration for all the STAs in theMU-MIMO group. Further, the techniques enable the use of EDMG Headers inthe MU PPDU or the use of an aggregated management frame in the MU PPDUto indicate the order of the STAs that will be requested for BlockACK,as well as the STAs that will be granted for RD. Based on this providedinformation, each MU-MIMO destination STA can calculate the time that isneeded for each STA to send BlockACK and RD data before and after itsown turn to send BlockACK and RD data. Based on this calculation, theMU-MIMO destination STAs can decide their power saving strategy duringDL MU-MIMO transmissions (e.g., based on one of the three optionsdescribed above).

Various embodiments of the invention may be implemented fully orpartially in software and/or firmware. This software and/or firmware maytake the form of instructions contained in or on a non-transitorycomputer-readable storage medium. Those instructions may then be readand executed by one or more processors to enable performance of theoperations described herein. The instructions may be in any suitableform, such as but not limited to source code, compiled code, interpretedcode, executable code, static code, dynamic code, and the like. Such acomputer-readable medium may include any tangible non-transitory mediumfor storing information in a form readable by one or more computers,such as but not limited to read only memory (ROM); random access memory(RAM); magnetic disk storage media; optical storage media; a flashmemory, etc. The embodiments are not limited in this context.

FIG. 6 illustrates an embodiment of a storage medium 600. Storage medium600 may comprise any non-transitory computer-readable storage medium ormachine-readable storage medium, such as an optical, magnetic orsemiconductor storage medium. In various embodiments, storage medium 600may comprise an article of manufacture. In some embodiments, storagemedium 600 may store computer-executable instructions, such ascomputer-executable instructions to implement logic flow 400 of FIG. 4and/or logic flow 500 of FIG. 5 . Examples of a computer-readablestorage medium or machine-readable storage medium may include anytangible media capable of storing electronic data, including volatilememory or non-volatile memory, removable or non-removable memory,erasable or non-erasable memory, writeable or re-writeable memory, andso forth. Examples of computer-executable instructions may include anysuitable type of code, such as source code, compiled code, interpretedcode, executable code, static code, dynamic code, object-oriented code,visual code, and the like. The embodiments are not limited in thiscontext.

FIG. 7 illustrates an embodiment of a communications device 700 that mayimplement one or more of wireless communication devices 102-108, logicflow 400, logic flow 500, and storage medium 600. In variousembodiments, device 700 may comprise a logic circuit 728. The logiccircuit 728 may include physical circuits to perform operationsdescribed for one or more of wireless communication devices 102-108,logic flow 400, and logic flow 500, for example. As shown in FIG. 7 ,device 700 may include a radio interface 710, baseband circuitry 720,and computing platform 730, although the embodiments are not limited tothis configuration.

The device 700 may implement some or all of the structure and/oroperations for one or more of wireless communication devices 102-108,logic flow 400, logic flow 500, storage medium 600, and logic circuit728 in a single computing entity, such as entirely within a singledevice. Alternatively, the device 700 may distribute portions of thestructure and/or operations for one or more of wireless communicationdevices 102-108, logic flow 400, logic flow 500, storage medium 600, andlogic circuit 728 across multiple computing entities using a distributedsystem architecture, such as a client-server architecture, a 3-tierarchitecture, an N-tier architecture, a tightly-coupled or clusteredarchitecture, a peer-to-peer architecture, a master-slave architecture,a shared database architecture, and other types of distributed systems.The embodiments are not limited in this context.

In one embodiment, radio interface 710 may include a component orcombination of components adapted for transmitting and/or receivingsingle-carrier or multi-carrier modulated signals (e.g., includingcomplementary code keying (CCK), orthogonal frequency divisionmultiplexing (OFDM), and/or single-carrier frequency division multipleaccess (SC-FDMA) symbols) although the embodiments are not limited toany specific over-the-air interface or modulation scheme. Radiointerface 710 may include, for example, a receiver 712, a frequencysynthesizer 714, and/or a transmitter 716. Radio interface 710 mayinclude bias controls, a crystal oscillator and/or one or more antennas718-f. In another embodiment, radio interface 710 may use externalvoltage-controlled oscillators (VCOs), surface acoustic wave filters,intermediate frequency (IF) filters and/or RF filters, as desired. Dueto the variety of potential RF interface designs an expansivedescription thereof is omitted.

Baseband circuitry 720 may communicate with radio interface 710 toprocess receive and/or transmit signals and may include, for example, ananalog-to-digital converter 722 for down converting received signals, adigital-to-analog converter 724 for up converting signals fortransmission. Further, baseband circuitry 720 may include a baseband orphysical layer (PHY) processing circuit 726 for PHY link layerprocessing of respective receive/transmit signals. Baseband circuitry720 may include, for example, a medium access control (MAC) processingcircuit 727 for MAC/data link layer processing. Baseband circuitry 720may include a memory controller 732 for communicating with MACprocessing circuit 727 and/or a computing platform 730, for example, viaone or more interfaces 734.

In some embodiments, PHY processing circuit 726 may include a frameconstruction and/or detection module, in combination with additionalcircuitry such as a buffer memory, to construct and/or deconstructcommunication frames. Alternatively or in addition, MAC processingcircuit 727 may share processing for certain of these functions orperform these processes independent of PHY processing circuit 726. Insome embodiments, MAC and PHY processing may be integrated into a singlecircuit.

The computing platform 730 may provide computing functionality for thedevice 700. As shown, the computing platform 730 may include aprocessing component 740. In addition to, or alternatively of, thebaseband circuitry 720, the device 700 may execute processing operationsor logic for one or more of wireless communication devices 102-108,logic flow 400, logic flow 500, storage medium 600, and logic circuit728 using the processing component 740. The processing component 740(and/or PHY 726 and/or MAC 727) may comprise various hardware elements,software elements, or a combination of both. Examples of hardwareelements may include devices, logic devices, components, processors,microprocessors, circuits, processor circuits, circuit elements (e.g.,transistors, resistors, capacitors, inductors, and so forth), integratedcircuits, application specific integrated circuits (ASIC), programmablelogic devices (PLD), digital signal processors (DSP), field programmablegate array (FPGA), memory units, logic gates, registers, semiconductordevice, chips, microchips, chip sets, and so forth. Examples of softwareelements may include software components, programs, applications,computer programs, application programs, system programs, softwaredevelopment programs, machine programs, operating system software,middleware, firmware, software modules, routines, subroutines,functions, methods, procedures, software interfaces, application programinterfaces (API), instruction sets, computing code, computer code, codesegments, computer code segments, words, values, symbols, or anycombination thereof. Determining whether an embodiment is implementedusing hardware elements and/or software elements may vary in accordancewith any number of factors, such as desired computational rate, powerlevels, heat tolerances, processing cycle budget, input data rates,output data rates, memory resources, data bus speeds and other design orperformance constraints, as desired for a given implementation.

The computing platform 730 may further include other platform components750. Other platform components 750 include common computing elements,such as one or more processors, multi-core processors, co-processors,memory units, chipsets, controllers, peripherals, interfaces,oscillators, timing devices, video cards, audio cards, multimediainput/output (I/O) components (e.g., digital displays), power supplies,and so forth. Examples of memory units may include without limitationvarious types of computer readable and machine readable storage media inthe form of one or more higher speed memory units, such as read-onlymemory (ROM), random-access memory (RAM), dynamic RAM (DRAM),Double-Data-Rate DRAM (DDRAM), synchronous DRAM (SDRAM), static RAM(SRAM), programmable ROM (PROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), flash memory, polymermemory such as ferroelectric polymer memory, ovonic memory, phase changeor ferroelectric memory, silicon-oxide-nitride-oxide-silicon (SONOS)memory, magnetic or optical cards, an array of devices such as RedundantArray of Independent Disks (RAID) drives, solid state memory devices(e.g., USB memory, solid state drives (SSD) and any other type ofstorage media suitable for storing information.

Device 700 may be, for example, an ultra-mobile device, a mobile device,a fixed device, a machine-to-machine (M2M) device, a personal digitalassistant (PDA), a mobile computing device, a smart phone, a telephone,a digital telephone, a cellular telephone, user equipment, eBookreaders, a handset, a one-way pager, a two-way pager, a messagingdevice, a computer, a personal computer (PC), a desktop computer, alaptop computer, a notebook computer, a netbook computer, a handheldcomputer, a tablet computer, a server, a server array or server farm, aweb server, a network server, an Internet server, a work station, amini-computer, a main frame computer, a supercomputer, a networkappliance, a web appliance, a distributed computing system,multiprocessor systems, processor-based systems, consumer electronics,programmable consumer electronics, game devices, display, television,digital television, set top box, wireless access point, base station,node B, subscriber station, mobile subscriber center, radio networkcontroller, router, hub, gateway, bridge, switch, machine, orcombination thereof. Accordingly, functions and/or specificconfigurations of device 700 described herein, may be included oromitted in various embodiments of device 700, as suitably desired.

Embodiments of device 700 may be implemented using single input singleoutput (SISO) architectures. However, certain implementations mayinclude multiple antennas (e.g., antennas 718-f) for transmission and/orreception using adaptive antenna techniques for beamforming or spatialdivision multiple access (SDMA) and/or using MIMO communicationtechniques.

The components and features of device 700 may be implemented using anycombination of discrete circuitry, application specific integratedcircuits (ASICs), logic gates and/or single chip architectures. Further,the features of device 700 may be implemented using microcontrollers,programmable logic arrays and/or microprocessors or any combination ofthe foregoing where suitably appropriate. It is noted that hardware,firmware and/or software elements may be collectively or individuallyreferred to herein as “logic” or “circuit.”

It should be appreciated that the exemplary device 700 shown in theblock diagram of FIG. 7 may represent one functionally descriptiveexample of many potential implementations. Accordingly, division,omission or inclusion of block functions depicted in the accompanyingfigures does not infer that the hardware components, circuits, softwareand/or elements for implementing these functions would be necessarily bedivided, omitted, or included in embodiments.

In various embodiments, device 700 can be an AP/PCP or a STA of an802.11ay network.

FIG. 8 illustrates an embodiment of a wireless network 800. As shown inFIG. 8 , wireless network comprises an access point 802 and wirelessstations 804, 806, and 808. In various embodiments, wireless network 800may comprise a wireless local area network (WLAN), such as a WLANimplementing one or more Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 standards (sometimes collectively referred to as“Wi-Fi”). In some other embodiments, wireless network 800 may compriseanother type of wireless network, and/or may implement other wirelesscommunications standards. In various embodiments, for example, wirelessnetwork 800 may comprise a WWAN or WPAN rather than a WLAN. Theembodiments are not limited to this example.

In various embodiments, the wireless network 800 is an 802.11ay networkand can be a network in which the WCDs 102-108 operate.

In some embodiments, wireless network 800 may implement one or morebroadband wireless communications standards, such as 3G or 4G standards,including their revisions, progeny, and variants. Examples of 3G or 4Gwireless standards may include without limitation any of the IEEE802.16m and 802.16p standards, 3rd Generation Partnership Project (3GPP)Long Term Evolution (LTE) and LTE-Advanced (LTE-A) standards, andInternational Mobile Telecommunications Advanced (IMT-ADV) standards,including their revisions, progeny and variants. Other suitable examplesmay include, without limitation, Global System for Mobile Communications(GSM)/Enhanced Data Rates for GSM Evolution (EDGE) technologies,Universal Mobile Telecommunications System (UMTS)/High Speed PacketAccess (HSPA) technologies, Worldwide Interoperability for MicrowaveAccess (WiMAX) or the WiMAX II technologies, Code Division MultipleAccess (CDMA) 2000 system technologies (e.g., CDMA2000 1×RTT, CDMA2000EV-DO, CDMA EV-DV, and so forth), High Performance Radio MetropolitanArea Network (HIPERMAN) technologies as defined by the EuropeanTelecommunications Standards Institute (ETSI) Broadband Radio AccessNetworks (BRAN), Wireless Broadband (WiBro) technologies, GSM withGeneral Packet Radio Service (GPRS) system (GSM/GPRS) technologies, HighSpeed Downlink Packet Access (HSDPA) technologies, High Speed OrthogonalFrequency-Division Multiplexing (OFDM) Packet Access (HSOPA)technologies, High-Speed Uplink Packet Access (HSUPA) systemtechnologies, 3GPP Rel. 8-12 of LTE/System Architecture Evolution (SAE),and so forth. The embodiments are not limited in this context.

In various embodiments, wireless stations 804, 806, and 808 maycommunicate with access point 802 in order to obtain connectivity to oneor more external data networks. In some embodiments, for example,wireless stations 804, 806, and 808 may connect to the Internet 812 viaaccess point 802 and access network 810. In various embodiments, accessnetwork 810 may comprise a private network that providessubscription-based Internet-connectivity, such as an Internet ServiceProvider (ISP) network. The embodiments are not limited to this example.

In various embodiments, two or more of wireless stations 804, 806, and808 may communicate with each other directly by exchanging peer-to-peercommunications. For example, in the example of FIG. 8 , wirelessstations 804 and 806 communicate with each other directly by exchangingpeer-to-peer communications 814. In some embodiments, such peer-to-peercommunications may be performed according to one or more Wi-Fi Alliance(WFA) standards. For example, in various embodiments, such peer-to-peercommunications may be performed according to the WFA Wi-Fi Directstandard, 2010 Release. In various embodiments, such peer-to-peercommunications may additionally or alternatively be performed using oneor more interfaces, protocols, and/or standards developed by the WFAWi-Fi Direct Services (WFDS) Task Group. The embodiments are not limitedto these examples.

Various embodiments may be implemented using hardware elements, softwareelements, or a combination of both. Examples of hardware elements mayinclude processors, microprocessors, circuits, circuit elements (e.g.,transistors, resistors, capacitors, inductors, and so forth), integratedcircuits, application specific integrated circuits (ASIC), programmablelogic devices (PLD), digital signal processors (DSP), field programmablegate array (FPGA), logic gates, registers, semiconductor device, chips,microchips, chip sets, and so forth. Examples of software may includesoftware components, programs, applications, computer programs,application programs, system programs, machine programs, operatingsystem software, middleware, firmware, software modules, routines,subroutines, functions, methods, procedures, software interfaces,application program interfaces (API), instruction sets, computing code,computer code, code segments, computer code segments, words, values,symbols, or any combination thereof. Determining whether an embodimentis implemented using hardware elements and/or software elements may varyin accordance with any number of factors, such as desired computationalrate, power levels, heat tolerances, processing cycle budget, input datarates, output data rates, memory resources, data bus speeds and otherdesign or performance constraints.

One or more aspects of at least one embodiment may be implemented byrepresentative instructions stored on a machine-readable medium whichrepresents various logic within the processor, which when read by amachine causes the machine to fabricate logic to perform the techniquesdescribed herein. Such representations, known as “IP cores” may bestored on a tangible, machine readable medium and supplied to variouscustomers or manufacturing facilities to load into the fabricationmachines that actually make the logic or processor. Some embodiments maybe implemented, for example, using a machine-readable medium or articlewhich may store an instruction or a set of instructions that, ifexecuted by a machine, may cause the machine to perform a method and/oroperations in accordance with the embodiments. Such a machine mayinclude, for example, any suitable processing platform, computingplatform, computing device, processing device, computing system,processing system, computer, processor, or the like, and may beimplemented using any suitable combination of hardware and/or software.The machine-readable medium or article may include, for example, anysuitable type of memory unit, memory device, memory article, memorymedium, storage device, storage article, storage medium and/or storageunit, for example, memory, removable or non-removable media, erasable ornon-erasable media, writeable or re-writeable media, digital or analogmedia, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM),Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW),optical disk, magnetic media, magneto-optical media, removable memorycards or disks, various types of Digital Versatile Disk (DVD), a tape, acassette, or the like. The instructions may include any suitable type ofcode, such as source code, compiled code, interpreted code, executablecode, static code, dynamic code, encrypted code, and the like,implemented using any suitable high-level, low-level, object-oriented,visual, compiled and/or interpreted programming language.

The following examples pertain to further embodiments:

Example 1 is an apparatus, comprising a memory and baseband circuitrycoupled to the memory, the baseband circuitry to determine an order fora plurality of stations (STAs) comprised in a multiple-usermultiple-input and multiple-output (MU-MIMO) STA group and generate adata message to be transmitted over a wireless carrier, the data messageto comprise a listing of association identifiers (AIDs), each AID in thelisting to correspond to a one of the plurality of STAs comprised in theMU-MIMO STA group, the listing to indicate an order of the STAs, a blockacknowledgement (BACK) field to indicate the STAs to instruct to send aBACK, and a reverse direction (RD) field to indicate the STAs toinstruct to send an RD transmission.

Example 2 is an extension of Example 1 or any other example disclosedherein, the listing of AIDs to include a sequential listing of the AIDs.

Example 3 is an extension of Example 1 or any other example disclosedherein, the BACK field to include a sequence of bits, each bit tocorrespond to a one of the AIDs in the listing of AIDs.

Example 4 is an extension of Example 3 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 5 is an extension of Example 3 or any other example disclosedherein, a first bit value to indicate an instruction to send the BACKand a second bit value to indicate an instruction to not send the BACK.

Example 6 is an extension of Example 1 or any other example disclosedherein, the RD field to include a sequence of bits, each bit tocorrespond to a one of the AIDs in the listing of AIDs.

Example 7 is an extension of Example 6 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 8 is an extension of Example 6 or any other example disclosedherein, a first bit value to indicate an instruction to send the RDtransmission and a second bit value to indicate an instruction to notsend the RD transmission.

Example 9 is an extension of Example 1 or any other example disclosedherein, the data message to comprise an enhanced multi-gigabit (EDMG)Header A, the EDMG Header A to include at least one of the listing ofAIDs, the BACK field, and the RD field.

Example 10 is an extension of Example 9 or any other example disclosedherein, the data message to comprise an EDMG Header B, the EDMG Header Bto include at least one of the BACK field and the RD field.

Example 11 is an extension of Example 1 or any other example disclosedherein, the baseband circuitry to generate an indication of a durationof the RD transmission for each STA.

Example 12 is an extension of Example 11 or any other example disclosedherein, the baseband circuitry to generate an EDMG Header A to includethe indication of the duration of the RD transmission for each STA.

Example 13 is an extension of Example 11 or any other example disclosedherein, the baseband circuitry to generate an EDMG Header B to includethe indication of the duration of the RD transmission for each STA.

Example 14 is an extension of Example 11 or any other example disclosedherein, the baseband circuitry to generate a setup data frame to includethe indication of the duration of the RD transmission for each STA.

Example 15 is an extension of any of Examples 1 to 14 or any otherexample disclosed herein, the apparatus comprising at least one radiofrequency (RF) transceiver and at least on RF antenna.

Example 16 is a wireless communication method, comprising determining anorder for a plurality of stations (STAs) comprised in a multiple-usermultiple-input and multiple-output (MU-MIMO) STA group and generating adata message to be transmitted over a wireless carrier, the data messageto comprise a listing of association identifiers (AIDs), each AID in thelisting to correspond to a one of the plurality of STAs comprised in theMU-MIMO STA group, the listing to indicate an order of the STAs, a blockacknowledgement (BACK) field to indicate the STAs to instruct to send aBACK, and a reverse direction (RD) field to indicate the STAs toinstruct to send an RD transmission.

Example 17 is an extension of Example 16 or any other example disclosedherein, the listing of AIDs to include a sequential listing of the AIDs.

Example 18 is an extension of Example 16 or any other example disclosedherein, the BACK field to include a sequence of bits, each bit tocorrespond to a one of the AIDs in the listing of AIDs.

Example 19 is an extension of Example 18 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 20 is an extension of Example 18 or any other example disclosedherein, a first bit value to indicate an instruction to send the BACKand a second bit value to indicate an instruction to not send the BACK.

Example 21 is an extension of Example 15 or any other example disclosedherein, the RD field to include a sequence of bits, each bit tocorrespond to a one of the AIDs in the listing of AIDs.

Example 22 is an extension of Example 21 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 23 is an extension of Example 21 or any other example disclosedherein, a first bit value to indicate an instruction to send the RDtransmission and a second bit value to indicate an instruction to notsend the RD transmission.

Example 24 is an extension of Example 16 or any other example disclosedherein, the data message to comprise an enhanced multi-gigabit (EDMG)Header A, the EDMG Header A to include at least one of the listing ofAIDs, the BACK field, and the RD field.

Example 25 is an extension of Example 24 or any other example disclosedherein, the data message to comprise an EDMG Header B, the EDMG Header Bto include at least one of the BACK field and the RD field.

Example 26 is an extension of Example 16 or any other example disclosedherein, generating an indication of a duration of the RD transmissionfor each STA.

Example 27 is an extension of Example 26 or any other example disclosedherein, generating an EDMG Header A to include the indication of theduration of the RD transmission for each STA.

Example 28 is an extension of Example 26 or any other example disclosedherein, generating an EDMG Header B to include the indication of theduration of the RD transmission for each STA.

Example 29 is an extension of Example 26 or any other example disclosedherein, generating a setup data frame to include the indication of theduration of the RD transmission for each STA.

Example 30 is a least one computer-readable storage medium comprising aset of instructions that, in response to being executed on a computingdevice, cause the computing device to perform a wireless communicationmethod according to any of Examples 16 to 29 or any other exampledisclosed herein.

Example 31 is an apparatus, comprising means for performing a wirelesscommunication method according to any of Examples 16 to 29 any otherexample disclosed herein.

Example 32 is at least one non-transitory computer-readable mediumcomprising a set of instructions that, in response to being executed ata wireless communication device, cause the wireless communication deviceto determine an order for a plurality of stations (STAs) comprised in amultiple-user multiple-input and multiple-output (MU-MIMO) STA group andgenerate a data message to be transmitted over a wireless carrier, thedata message to comprise a listing of association identifiers (AIDs),each AID in the listing to correspond to a one of the plurality of STAscomprised in the MU-MIMO STA group, the listing to indicate an order ofthe STAs, a block acknowledgement (BACK) field to indicate the STAs toinstruct to send a BACK, and a reverse direction (RD) field to indicatethe STAs to instruct to send an RD transmission.

Example 33 is an extension of Example 32 or any other example disclosedherein, the listing of AIDs to include a sequential listing of the AIDs.

Example 34 is an extension of Example 32 or any other example disclosedherein, the BACK field to include a sequence of bits, each bit tocorrespond to a one of the AIDs in the listing of AIDs.

Example 35 is an extension of Example 34 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 36 is an extension of Example 34 or any other example disclosedherein, a first bit value to indicate an instruction to send the BACKand a second bit value to indicate an instruction to not send the BACK.

Example 37 is an extension of Example 32 or any other example disclosedherein, the RD field to include a sequence of bits, each bit tocorrespond to a one of the AIDs in the listing of AIDs.

Example 38 is an extension of Example 37 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 39 is an extension of Example 37 or any other example disclosedherein, a first bit value to indicate an instruction to send the RDtransmission and a second bit value to indicate an instruction to notsend the RD transmission.

Example 40 is an extension of Example 32 or any other example disclosedherein, the data message to comprise an enhanced multi-gigabit (EDMG)Header A, the EDMG Header A to include at least one of the listing ofAIDs, the BACK field, and the RD field.

Example 41 is an extension of Example 40 or any other example disclosedherein, the data message to comprise an EDMG Header B, the EDMG Header Bto include at least one of the BACK field and the RD field.

Example 42 is an extension of Example 32 or any other example disclosedherein, the baseband circuitry to generate an indication of a durationof the RD transmission for each STA.

Example 43 is an extension of Example 42 or any other example disclosedherein, comprising instructions that, in response to being executed onthe wireless communication device, cause the wireless communicationdevice to generate an EDMG Header A to include the indication of theduration of the RD transmission for each STA.

Example 44 is an extension of Example 42 or any other example disclosedherein, comprising instructions that, in response to being executed onthe wireless communication device, cause the wireless communicationdevice to generate an EDMG Header B to include the indication of theduration of the RD transmission for each STA.

Example 45 is an extension of Example 42 or any other example disclosedherein, comprising instructions that, in response to being executed onthe wireless communication device, cause the wireless communicationdevice to generate a setup data frame to include the indication of theduration of the RD transmission for each STA.

Example 46 is an apparatus, comprising a memory and baseband circuitrycoupled to the memory, the baseband circuitry to process a listing ofassociation identifiers (AIDs), each AID corresponding to a one of aplurality of stations (STAs) comprised in a multiple-user multiple-inputand multiple-output (MU-MIMO) STA group, to determine an order of theplurality of STAs, process a block acknowledgement (BACK) field todetermine the STAs instructed to send a BACK based on the determinedorder of the plurality of STAs, process a reverse direction (RD) fieldto determine the STAs instructed to send an RD transmission, determine aduration of the RD transmission of each STA, and determine a time tooperate in a power saving mode based on the determined order of the STAsinstructed to send a BACK, the determined STAs instructed to send the RDtransmission, and the determined duration of the RD transmissions.

Example 47 is an extension of Example 46 or any other example disclosedherein, the listing of AIDs to include a sequential listing of the AIDs.

Example 48 is an extension of Example 46 or any other example disclosedherein, the BACK field to include a sequence of bits, each bit tocorrespond to one of the AIDs in the listing of AIDs.

Example 49 is an extension of Example 48 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 50 is an extension of Example 48 or any other example disclosedherein, a first bit value to indicate an instruction to send the BACKand a second bit value to indicate an instruction to not send the BACK.

Example 51 is an extension of Example 46 or any other example disclosedherein, the RD field to include a sequence of bits, each bit tocorrespond to one of the AIDs in the listing of AIDs.

Example 52 is an extension of Example 51 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 53 is an extension of Example 51 or any other example disclosedherein, a first bit value to indicate an instruction to send the RDtransmission and a second bit value to indicate an instruction to notsend the RD transmission.

Example 54 is an extension of Example 46 or any other example disclosedherein, an enhanced multi-gigabit (EDMG) Header A to include the listingof AIDs and at least one of the BACK field and the RD field.

Example 55 is an extension of Example 54 or any other example disclosedherein, the EDMG Header A to include the duration of the RD transmissionof each STA.

Example 56 is an extension of Example 46 or any other example disclosedherein, an EDMG Header B to include at least one of the BACK field andthe RD field.

Example 57 is an extension of Example 56 or any other example disclosedherein, the EDMG Header B to include the duration of the RD transmissionof each STA.

Example 58 is an extension of Example 46 or any other example disclosedherein, the determined time to operate in the power saving mode based onoperating in the power saving mode during the RD transmissions of theSTAs.

Example 59 is an extension of Example 46 or any other example disclosedherein, the determined time to operate in the power saving mode based onnot operating in the power saving mode during the RD transmissions ofthe STAs.

Example 60 is an extension of Example 46 or any other example disclosedherein, the determined time to operate in the power saving mode based onoperating in the power saving mode during a portion of the RDtransmission of the STAs.

Example 61 is an extension of any of Examples 46 to 60 or any otherexample disclosed herein, comprising at least one radio frequency (RF)transceiver and at least on RF antenna.

Example 62 is a wireless communication method, comprising processing alisting of association identifiers (AIDs), each AID corresponding to aone of a plurality of stations (STAs) comprised in a multiple-usermultiple-input and multiple-output (MU-MIMO) STA group, to determine anorder of the plurality of STAs, processing a block acknowledgement(BACK) field to determine the STAs instructed to send a BACK based onthe determined order of the plurality of STAs, processing a reversedirection (RD) field to determine the STAs instructed to send an RDtransmission, determining a duration of the RD transmission of each STA,and determining a time to operate in a power saving mode based on thedetermined order of the STAs instructed to send a BACK, the determinedSTAs instructed to send the RD transmission, and the determined durationof the RD transmissions.

Example 63 is an extension of Example 62 or any other example disclosedherein, the listing of AIDs to include a sequential listing of the AIDs.

Example 64 is an extension of Example 62 or any other example disclosedherein, the BACK field to include a sequence of bits, each bit tocorrespond to one of the AIDs in the listing of AIDs.

Example 65 is an extension of Example 64 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 66 is an extension of Example 64 or any other example disclosedherein, a first bit value to indicate an instruction to send the BACKand a second bit value to indicate an instruction to not send the BACK.

Example 67 is an extension of Example 62 or any other example disclosedherein, the RD field to include a sequence of bits, each bit tocorrespond to one of the AIDs in the listing of AIDs.

Example 68 is an extension of Example 67 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 69 is an extension of Example 67 or any other example disclosedherein, a first bit value to indicate an instruction to send the RDtransmission and a second bit value to indicate an instruction to notsend the RD transmission.

Example 70 is an extension of Example 62 or any other example disclosedherein, an enhanced multi-gigabit (EDMG) Header A to include the listingof AIDs and at least one of the BACK field and the RD field.

Example 71 is an extension of Example 70 or any other example disclosedherein, the EDMG Header A to include the duration of the RD transmissionof each STA.

Example 72 is an extension of Example 62 or any other example disclosedherein, an EDMG Header B to include at least one of the BACK field andthe RD field.

Example 73 is an extension of Example 72 or any other example disclosedherein, the EDMG Header B to include the duration of the RD transmissionof each STA.

Example 74 is an extension of Example 62 or any other example disclosedherein, determining the time to operate in the power saving mode basedon operating in the power saving mode during the RD transmissions of theSTAs.

Example 75 is an extension of Example 62 or any other example disclosedherein, determining the time to operate in the power saving mode basedon not operating in the power saving mode during the RD transmissions ofthe STAs.

Example 76 is an extension of Example 62 or any other example disclosedherein, determining the time to operate in the power saving mode basedon operating in the power saving mode during a portion of the RDtransmission of the STAs.

Example 77 is at least one computer-readable storage medium comprising aset of instructions that, in response to being executed on a computingdevice, cause the computing device to perform a wireless communicationmethod according to any of Examples 62 to 76 or any other exampledisclosed herein.

Example 78 is an apparatus, comprising means for performing a wirelesscommunication method according to any of Examples 62 to 76 or any otherexample disclosed herein.

Example 79 is at least one non-transitory computer-readable mediumcomprising a set of instructions that, in response to being executed ata wireless communication device, cause the wireless communication deviceto process a listing of association identifiers (AIDs), each AIDcorresponding to a one of a plurality of stations (STAs) comprised in amultiple-user multiple-input and multiple-output (MU-MIMO) STA group, todetermine an order of the plurality of STAs, process a blockacknowledgement (BACK) field to determine the STAs instructed to send aBACK based on the determined order of the plurality of STAs, process areverse direction (RD) field to determine the STAs instructed to send anRD transmission, determine a duration of the RD transmission of eachSTA, and determine a time to operate in a power saving mode based on thedetermined order of the STAs instructed to send a BACK, the determinedSTAs instructed to send the RD transmission, and the determined durationof the RD transmissions.

Example 80 is an extension of Example 79 or any other example disclosedherein, the listing of AIDs to include a sequential listing of the AIDs.

Example 81 is an extension of Example 79 or any other example disclosedherein, the BACK field to include a sequence of bits, each bit tocorrespond to one of the AIDs in the listing of AIDs.

Example 82 is an extension of Example 81 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 83 is an extension of Example 81 or any other example disclosedherein, a first bit value to indicate an instruction to send the BACKand a second bit value to indicate an instruction to not send the BACK.

Example 84 is an extension of Example 79 or any other example disclosedherein, the RD field to include a sequence of bits, each bit tocorrespond to one of the AIDs in the listing of AIDs.

Example 85 is an extension of Example 84 or any other example disclosedherein, the sequence of bits to include 8 bits.

Example 86 is an extension of Example 84 or any other example disclosedherein, a first bit value to indicate an instruction to send the RDtransmission and a second bit value to indicate an instruction to notsend the RD transmission.

Example 87 is an extension of Example 79 or any other example disclosedherein, an enhanced multi-gigabit (EDMG) Header A to include the listingof AIDs and at least one of the BACK field and the RD field.

Example 88 is an extension of Example 87 or any other example disclosedherein, the EDMG Header A to include the duration of the RD transmissionof each STA.

Example 89 is an extension of Example 79 or any other example disclosedherein, an EDMG Header B to include at least one of the BACK field andthe RD field.

Example 90 is an extension of Example 87 or any other example disclosedherein, the EDMG Header B to include the duration of the RD transmissionof each STA.

Example 91 is an extension of Example 79 or any other example disclosedherein, comprising instructions that, in response to being executed onthe wireless communication device, cause the wireless communicationdevice to determine the time to operate in the power saving mode basedon operating in the power saving mode during the RD transmissions of theSTAs.

Example 92 is an extension of Example 79 or any other example disclosedherein, comprising instructions that, in response to being executed onthe wireless communication device, cause the wireless communicationdevice to determine the time to operate in the power saving mode basedon not operating in the power saving mode during the RD transmissions ofthe STAs.

Example 93 is an extension of Example 79 or any other example disclosedherein, comprising instructions that, in response to being executed onthe wireless communication device, cause the wireless communicationdevice to determine the time to operate in the power saving mode basedon operating in the power saving mode during a portion of the RDtransmission of the STAs.

Numerous specific details have been set forth herein to provide athorough understanding of the embodiments. It will be understood bythose skilled in the art, however, that the embodiments may be practicedwithout these specific details. In other instances, well-knownoperations, components, and circuits have not been described in detailso as not to obscure the embodiments. It can be appreciated that thespecific structural and functional details disclosed herein may berepresentative and do not necessarily limit the scope of theembodiments.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. These terms are not intendedas synonyms for each other. For example, some embodiments may bedescribed using the terms “connected” and/or “coupled” to indicate thattwo or more elements are in direct physical or electrical contact witheach other. The term “coupled,” however, may also mean that two or moreelements are not in direct contact with each other, but yet stillco-operate or interact with each other.

Unless specifically stated otherwise, it may be appreciated that termssuch as “processing,” “computing,” “calculating,” “determining,” or thelike, refer to the action and/or processes of a computer or computingsystem, or similar electronic computing device, that manipulates and/ortransforms data represented as physical quantities (e.g., electronic)within the computing system's registers and/or memories into other datasimilarly represented as physical quantities within the computingsystem's memories, registers or other such information storage,transmission or display devices. The embodiments are not limited in thiscontext.

It should be noted that the methods described herein do not have to beexecuted in the order described, or in any particular order. Moreover,various activities described with respect to the methods identifiedherein can be executed in serial or parallel fashion.

Although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement calculated toachieve the same purpose may be substituted for the specific embodimentsshown. This disclosure is intended to cover any and all adaptations orvariations of various embodiments. It is to be understood that the abovedescription has been made in an illustrative fashion, and not arestrictive one. Combinations of the above embodiments, and otherembodiments not specifically described herein will be apparent to thoseof skill in the art upon reviewing the above description. Thus, thescope of various embodiments includes any other applications in whichthe above compositions, structures, and methods are used.

It is emphasized that the Abstract of the Disclosure is provided tocomply with 37 C.F.R. § 1.72(b), requiring an abstract that will allowthe reader to quickly ascertain the nature of the technical disclosure.It is submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description, it can be seen that various featuresare grouped together in a single embodiment for the purpose ofstreamlining the disclosure. This method of disclosure is not to beinterpreted as reflecting an intention that the claimed embodimentsrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive subject matter lies in lessthan all features of a single disclosed embodiment. Thus the followingclaims are hereby incorporated into the Detailed Description, with eachclaim standing on its own as a separate preferred embodiment. In theappended claims, the terms “including” and “in which” are used as theplain-English equivalents of the respective terms “comprising” and“wherein,” respectively. Moreover, the terms “first,” “second,” and“third,” etc. are used merely as labels, and are not intended to imposenumerical requirements on their objects.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. An apparatus, comprising: a memory of a firststation (STA); and processing circuitry of the first STA coupled to thememory, the processing circuitry to: generate a first multiple-user PHYprotocol data unit (MU-PPDU) to communicate in a downlink (DL)multiple-user multiple-input and multiple-output (MU-MIMO) communicationto initiate a reverse direction (RD) communication, the MU-PPDUcomprising aggregated frames, the aggregated frames comprising a frameto request a block acknowledgement and a quality of service (QoS) framecomprising a grant for a RD communication; cause transmission of thefirst MU-PPDU to a second STA; process the reverse directioncommunication including a first block acknowledgement and data inresponse to the first MU-PPDU; and cause transmission of a second blockacknowledgement to acknowledge the reverse direction communication. 2.The apparatus of claim 1, the first MU-PPDU comprising a bit of areverse direction (RD) indication set to 1 to grant the RDcommunication.
 3. The apparatus of claim 1, the first MU-PPDU comprisinga Response Duration for a RD responder.
 4. The apparatus of claim 1, thefirst MU-PPDU comprising an enhanced directional multigigabit (EDMG)Header A.
 5. The apparatus of claim 4, the first STA comprising anaccess point and the second STA comprising an EDMG STA.
 6. The apparatusof claim 1, wherein a block acknowledgement request frame and a QoS Nullframe are aggregated in a MAC protocol data unit (MPDU) of the MU-PPDU.7. The apparatus of claim 1, wherein the first STA is a personal basicservice set (PBSS) control point (PCP).
 8. The apparatus of claim 1,comprising: a transceiver; and one or more antennas coupled with thetransceiver.
 9. The apparatus of claim 8, the processing circuitry tocause transmission of the grant for the RD communication to the firstSTA via the transceiver and one or more antennas.
 10. A non-transitorycomputer-readable storage medium, comprising a plurality ofinstructions, that when executed, enable processing circuitry to:generate a first multiple-user PHY protocol data unit (MU-PPDU) tocommunicate in a downlink (DL) multiple-user multiple-input andmultiple-output (MU-MIMO) communication to initiate a reverse direction(RD) communication, the MU-PPDU comprising aggregated frames, theaggregated frames comprising a frame to request a block acknowledgementand a quality of service (QoS) frame comprising a grant for a RDcommunication; cause transmission of the first MU-PPDU to a secondstation (STA); process the reverse direction communication including afirst block acknowledgement and data in response to the first MU-PPDU;and cause transmission of a second block acknowledgement to acknowledgethe reverse direction communication.
 11. The non-transitorycomputer-readable storage medium of claim 10, the first MU-PPDUcomprising a Response Duration for a RD responder.
 12. Thenon-transitory computer-readable storage medium of claim 10, the firstMU-PPDU comprising an enhanced directional multigigabit (EDMG) Header A.13. The non-transitory computer-readable storage medium of claim 10, afirst STA comprising the processing circuitry is an access point and thesecond STA comprises an EDMG STA.
 14. The non-transitorycomputer-readable storage medium of claim 10, wherein a blockacknowledgement request frame and a QoS Null frame are aggregated in aMAC protocol data unit (MPDU) of the MU-PPDU.
 15. An apparatus,comprising: a memory of a first station (STA); and processing circuitryof the first STA coupled to the memory, the processing circuitry to:process a first multiple-user PHY protocol data unit (MU-PPDU) tocommunicate in a downlink (DL) multiple-user multiple-input andmultiple-output (MU-MIMO) communication to initiate a reverse direction(RD) communication, wherein the MU-PPDU comprises aggregated frames, theaggregated frames comprising a frame to request a block acknowledgementand a quality of service (QoS) frame comprising a grant for a RDcommunication; cause transmission of the reverse direction communicationincluding a first block acknowledgement and data in response toreception of the first MU-PPDU; and process a second blockacknowledgement communicated to acknowledge the reverse directioncommunication.
 16. The apparatus of claim 15, the first MU-PPDUcomprising a bit of a reverse direction (RD) indication set to 1 togrant the RD communication.
 17. The apparatus of claim 15, the firstMU-PPDU comprising a Response Duration for a RD responder.
 18. Theapparatus of claim 15, the first MU-PPDU comprising an enhanceddirectional multigigabit (EDMG) Header A.
 19. The apparatus of claim 18,the first MU-PPDU is received from an access point and the first STA isan EDMG STA.
 20. The apparatus of claim 15, wherein a blockacknowledgement request frame and a QoS Null frame are aggregated in aMAC protocol data unit (MPDU) of the MU-PPDU.
 21. The apparatus of claim15, comprising: a transceiver; and one or more antennas coupled with thetransceiver.
 22. A non-transitory computer-readable storage medium,comprising a plurality of instructions, that when executed, enableprocessing circuitry to: process a first multiple-user PHY protocol dataunit (MU-PPDU) to communicate in a downlink (DL) multiple-usermultiple-input and multiple-output (MU-MIMO) communication to initiate areverse direction (RD) communication, wherein the MU-PPDU comprisesaggregated frames, the aggregated frames comprising a frame to request ablock acknowledgement and a quality of service (QoS) frame comprising agrant for a RD communication; cause transmission of the reversedirection communication including a first block acknowledgement and datain response to reception of the first MU-PPDU; and process a secondblock acknowledgement communicated to acknowledge the reverse directioncommunication.
 23. The non-transitory computer-readable storage mediumof claim 22, the first MU-PPDU comprising a bit of a reverse direction(RD) indication set to 1 to grant the RD communication.
 24. Thenon-transitory computer-readable storage medium of claim 22, the firstMU-PPDU comprising a Response Duration for a RD responder.
 25. Thenon-transitory computer-readable storage medium of claim 22, the firstMU-PPDU comprising an enhanced directional multigigabit (EDMG) Header A.26. The non-transitory computer-readable storage medium of claim 25, thefirst MU-PPDU is received from an access point and a first STAcomprising the processing circuitry is an EDMG STA.